Many of information systems, such as an electronic commerce system and the like, are constructed by using a plurality of servers such as a three-hierarchical system and the like. In such information systems, transactions are processed while repetitively transmitting and receiving messages among servers. The messages transmitted and received among the servers contain character strings such as a session ID, a transaction ID and the like, as transaction information common to each transaction unit. Accordingly, by utilizing these character strings, it is possible to perform “a linking process” of associating the messages transmitted and received among servers, with each transaction, and consequently, behavior monitoring of the information system, delay analysis of transaction execution, and the like can be performed.
In a conventional linking process, a character string retrieving tool, such as a grep command, is repetitively and manually applied to the messages transmitted and received among the servers in accordance with the transaction execution, so that the character string (linking keyword) contained commonly in the messages is specified. However, since a process of specifying the linking keyword is manually performed, a large number of man-hour is required, and thus, a management cost may be increased. Therefore, for the purpose of partitioning received messages, there has been proposed a technology for automatically extracting a keyword common to a plurality of received messages in the same partition.
As linking keywords for messages, it is necessary to utilize not only a unique character string for each transaction, such as the transaction ID, but also the same character string appearing plenty of times in the transactions which do not temporally overlap with each other, such as the session ID. However, in the conventionally proposed technology, since only the keyword common to the plurality of received messages in the same partition is extracted, the linking process utilizing the session ID is not performed, and consequently, it is difficult to link the messages for each transaction.